Refactor pprof labels and process desc (#32909)

* Deprecate "gopid" in log, it is not useful and requires very hacky
approach
* Remove "git.Command.SetDescription" because it is not useful and only
makes the logs too flexible

modules/gtprof/gtprof.go

@@ -0,0 +1,25 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package gtprof
+
+// This is a Gitea-specific profiling package,
+// the name is chosen to distinguish it from the standard pprof tool and "GNU gprof"
+
+// LabelGracefulLifecycle is a label marking manager lifecycle phase
+// Making it compliant with prometheus key regex https://prometheus.io/docs/concepts/data_model/#metric-names-and-labels
+// would enable someone interested to be able to continuously gather profiles into pyroscope.
+// Other labels for pprof should also follow this rule.
+const LabelGracefulLifecycle = "graceful_lifecycle"
+
+// LabelPid is a label set on goroutines that have a process attached
+const LabelPid = "pid"
+
+// LabelPpid is a label set on goroutines that have a process attached
+const LabelPpid = "ppid"
+
+// LabelProcessType is a label set on goroutines that have a process attached
+const LabelProcessType = "process_type"
+
+// LabelProcessDescription is a label set on goroutines that have a process attached
+const LabelProcessDescription = "process_description"